Unsupervised Learning of Morphology Harald Hammarström author Lars Borin author 2011-06 text journal article Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal hammarstrom-borin-2011-unsupervised 10.1162/COLI_a_00050 https://aclanthology.org/J11-2002/ 2011-06 37 2 309 350